Soft stabilization assemblies with off-set connector

ABSTRACT

A spinal longitudinal connecting member includes a soft stabilization assembly segment having a tensioned cord and a hard rod segment. A connector in fixed engagement with the hard rod also captures the tensioned cord of the soft segment, the connector being in fixed or sliding relation with the tensioned cord. The connector places the soft assembly segment in lateral or off-set and staggered relation to the hard rod segment. The connector may be integral to a bone anchor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This continuation application claims priority under 35 U.S.C. §120 fromco-pending U.S. Nonprovisional Application No. 14/171,168 entitled “SOFTSTABILIZATION ASSEMBLIES WITH OFF-SET CONNECTOR,” filed on Feb. 3, 2014,which claims priority under 35 U.S.C. §119 from U.S. ProvisionalApplication No. 61/849,934 entitled “SOFT STABILIZATION ASSEMBLIES WITHOFF-SET CONNECTOR,” filed Feb. 5, 2013.

U.S. Nonprovisional Application No. 14/171,168 is also acontinuation-in-part of and claims priority from U.S. NonprovisionalApplication No. 12/802,849 entitled “LONGITUDINAL CONNECTING MEMBER WITHSLEEVED TENSIONED CORDS,” filed Jun. 15, 2010 which claims priority fromU.S. Provisional Application No. 61/268,708 entitled “DYNAMICSTABILIZATION ASSEMBLY WITH CORD AND FLUSH SLIDING SLEEVES,” filed Jun.15, 2009; U.S. Provisional Application No. 61/270,754 entitled “DYNAMICSTABILIZATION ASSEMBLY WITH CORD AND FLANGED SLEEVES,” filed Jul. 13,2009; U.S. Provisional Application No. 61/336,911 entitled “POLYAXIALBONE ANCHOR WITH NON-PIVOTABLE SNAP-ON SPRING RING AND FRICTION FITINSERT,” filed Jan. 28, 2010; U.S. Provisional Application No.61/395,564 entitled “POLYAXIAL BONE ANCHOR WITH FRICTION FIT CROWNINSERT, POP-ON SHANK AND FLANGE FORM CLOSURE,” filed May 14, 2010; U.S.Provisional Application No. 61/395,752 entitled “POLYAXIAL BONE ANCHORWITH POP-ON DIRECT ENGAGEMENT SHANK,” filed May 17, 2010; and U.S.Provisional Application No. 61/396,390 entitled “POLYAXIAL BONE ANCHORWITH POP-ON DIRECT ENGAGEMENT SHANK,” filed May 26, 2010, all of whichare incorporated by reference herein for all purposes.

BACKGROUND OF THE INVENTION

The present invention is directed to soft or dynamic fixation assembliesfor use in bone surgery, particularly spinal surgery, and in particularto longitudinal connecting members for such assemblies, the connectingmembers being attached to at least two bone fasteners.

Historically, it has been common to fuse adjacent vertebrae that areplaced in fixed relation by the installation therealong of bone screwsor other bone anchors and cooperating longitudinal connecting members orother elongate members. Fusion results in the permanent immobilizationof one or more of the intervertebral joints. Because the anchoring ofbone screws, hooks and other types of anchors directly to a vertebra canresult in significant forces being placed on the vertebra, and suchforces may ultimately result in the loosening of the bone screw or otheranchor from the vertebra, fusion allows for the growth and developmentof a bone counterpart to the longitudinal connecting member that canmaintain the spine in the desired position even if the implantsultimately fail or are removed. Because fusion has been a desiredcomponent of spinal stabilization procedures, longitudinal connectingmembers have been designed that are of a material, size and shape tolargely resist flexure, extension, torsion, distraction and compression,and thus substantially immobilize the portion of the spine that is to befused. Thus, longitudinal connecting members are typically uniform alongan entire length thereof, and usually made from a single or integralpiece of material having a uniform diameter or width of a size toprovide substantially rigid support in all planes.

An alternative to fusion, which immobilizes at least a portion of thespine, and the use of more rigid longitudinal connecting members orother rigid structure has been a “soft” or “dynamic” stabilizationapproach in which a flexible loop-, S-, C- or U-shaped member or acoil-like and/or a spring-like member is utilized as an elasticlongitudinal connecting member fixed between a pair of pedicle screws inan attempt to create, as much as possible, a normal loading patternbetween the vertebrae in flexion, extension, distraction, compression,side bending and torsion. Another type of soft or dynamic system knownin the art includes bone anchors connected by flexible cords or strands,typically made from a plastic material. Such a cord or strand may bethreaded through cannulated spacers that are disposed between adjacentbone anchors when such a cord or strand is implanted, tensioned andattached to the bone anchors. The spacers typically span the distancebetween bone anchors, providing limits on the bending movement of thecord or strand and thus strengthening and supporting the overall system.Such cord or strand-type systems have typically required specializedbone anchors and tooling for tensioning and holding the cord or strandin the bone anchors.

The complex dynamic conditions associated with spinal movement createchallenges for the design of elongate elastic longitudinal connectingmembers that exhibit an adequate fatigue strength to providestabilization and protected motion of the spine, without fusion, andthat allow for some natural movement of the portion of the spine beingreinforced and supported by the elongate elastic or flexible connectingmember. A further challenge are situations in which a portion or lengthof the spine requires a more rigid stabilization, possibly includingfusion, while another portion or length may be better supported by amore dynamic system that allows for protective movement.

SUMMARY OF THE INVENTION

Longitudinal connecting member assemblies according to the invention foruse between at least two bone anchors provide soft or dynamic, protectedmotion of the spine and may be extended to provide additional soft ordynamic sections or more rigid support along an adjacent length of thespine, with fusion, if desired. An illustrated longitudinal connectingmember assembly according to an embodiment of the invention includes asoft portion or segment connected to a more rigid or hard portion orsegment by a transversely oriented connector structure, the connectorstructure placing the soft portion of the assembly in parallel butlateral or off-set and staggered relationship with the hard portion ofthe assembly. Stated in another way, when implanted onto a patient'sspine, the assembly generally runs along a portion of the spine with aconnector attaching a soft elongate segment with a hard elongatesegment; however, the soft and hard elongate segments of the assemblyare not directly in line with one another but rather are positionedmedial/lateral or lateral/medial with respect to one another. The softportion of the assembly includes an inner segment or core, typically atensioned cord or cords, the core being fixed at either end thereof tosubstantially rigid segments or structures, the rigid segments includingbut not limited to the off-set connector structure, bone anchors(typically bone screws, such as mono-axial or poly-axial screws), or endblocking structures or stops that are not part of a bone anchor or screwstructure. The core is also usually surrounded by a spacer that may beelastomeric or hard and rigid. Furthermore elastomeric bumpers may beused at locations along the soft portion of the assembly and about thetensioned cord or core to provide a continuous axial load. The tensionedinner core or cord of the soft portion of the assembly and one or morecompressed spacers and/or bumpers cooperate dynamically, such featuresalso having some flexibility in bending, but also protecting andlimiting flexing movement of the inner core. The rigid or hard portionof the assembly is typically a hard rod or bar that is attached to boththe off-set connector structure and to one or more bone anchors. Theoff-set connector may be closed or open at a top thereof, havingstructure for mating cooperation with set screws or other closure topsthat in turn have structure for fixing to the soft portion inner core orto the hard rod portion located within the off-set connector structure.In some embodiments, the off-set connector is integral with a boneanchor. Assemblies of embodiments of the invention may includemono-and/or poly-axial bone anchors, both open and closed. Typicallyopen mono- or poly-axial bone anchors are fixed to the hard rod portionof the assembly, while either open or closed bone anchors may be used tocapture, and if desired, fix the inner core of the assembly soft portionagainst the respective bone anchor. In certain embodiments it may bedesirable to allow the soft core or cord to be in sliding engagementwith the off-set connector and also with one or more bone anchors.

A variety of embodiments according to the invention are possible. Rodsor other substantially rigid structures having different measures ofrigidity may be connected according to embodiments of the invention.Either rigid lengths or flexible cords may be of greater or lesserlengths for attaching to one and up to a plurality of bone anchors.

It is an object of the invention to provide apparatus and methods thatare easy to use and especially adapted for the intended use thereof andwherein the apparatus are comparatively inexpensive to make and suitablefor use. Other objects and advantages of this invention will becomeapparent from the following description taken in conjunction with theaccompanying drawings wherein are set forth, by way of illustration andexample, certain embodiments of this invention.

The drawings constitute a part of this specification and includeexemplary embodiments of the present invention and illustrate variousobjects and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an off-set connector structure accordingto an embodiment of the invention.

FIG. 2 is a top plan view of the connector of FIG. 1.

FIG. 3 is a reduced perspective view of the connector of FIG. 1 shownoperatively attached to a longitudinal connecting member assembly thatincludes a rigid rod portion fixed to three open bone anchors and atensioned cord portion captured by two closed bone anchors, thetensioned cord portion including an end blocker or fixer, two elasticbumpers and a spacer.

FIG. 3a is also a reduced perspective view of the connector of FIG. 1shown operatively attached to an alternative longitudinal connectingmember assembly that includes a rigid rod portion fixed to three openbone anchors and a tensioned cord portion captured by one closed boneanchor, the tensioned cord portion including an end blocker or fixer, abumper and a spacer.

FIG. 4 shown in FIG. 3 is a front elevational view of the assembly

FIG. 5 is a top plan view of the assembly shown in FIG. 3.

FIG. 6 is a partial front elevational view of the assembly of FIG. 3,similar to FIG. 4 but with portions of the rigid rod portion broken awayto show the detail thereof.

FIG. 7 is partial front elevational view of the assembly of FIG. 3,similar to FIG. 4, but with portions of the tensioned cord portionbroken away to show the detail thereof.

FIG. 8 is a partial perspective view of another embodiment of aconnector shown with a hard rod, a tensioned cord and a portion of aspacer.

FIG. 9 is a reduced and partial perspective view of the connector ofFIG. 8 shown with a hard rod, a tensioned cord, an end blocker, a bumperand a partial spacer.

FIG. 10 is a perspective view of another alternative off-set connectorshown integral with a bone screw and showing a rigid rod and tensionedcord in phantom.

DETAILED DESCRIPTION OF THE INVENTION

required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure. It is also noted that any reference tothe words top, bottom, up and down, and the like, in this applicationrefers to the alignment shown in the various drawings, as well as thenormal connotations applied to such devices, and is not intended torestrict positioning of the connecting member assemblies of theapplication and cooperating bone anchors in actual use.

With reference to FIGS. 3-7, a longitudinal connecting member assemblyaccording to an embodiment of the invention, generally 1, is shown thatincludes a connector structure 2 that attaches a soft segment orassembly portion, generally 3, with a hard segment or portion, generally3′ in a staggered and offset orientation to one another. As best shownin FIG. 5, the soft non-fusion segment 3 is elongate and extendssubstantially along a central axis A. The hard segment portion 3′ isalso elongate and extends substantially along a central axis A′ that issubstantially parallel to the axis A. The elongated segments 3 and 3′are in a lateral/medial or medial/lateral relationship to one anotherwhen the assembly 1 is connected to a spine (not shown) utilizing boneanchors, such as open and closed mono-axial and polyaxial bone screwsand hooks.

The illustrated soft segment 3 of the assembly 1 includes the followingcomponents: an elongate bendable and soft, flexible core in the form ofa tensioned cord 4; a cannulated spacer 6 that may be compressible; twoelastic bumpers 8; and a fixing structure or blocking member in the formof a blocker 10 with cooperating set screw 11 sized and shaped forpressing against and/or into the cord 4 and fixing the cord with respectto the blocker 10. The hard portion or segment 3′ is illustrated as acylindrical rod 14.

The assembly 1 is shown with two closed monoaxial bone screws 16 andthree open monoaxial bone screws 18. The closed screws 16 each have anupper portion or head 21 integral with a lower shank 22 having at leastone helical thread form for rotating and driving the screw into avertebra. Each head 21 has a cylindrical opening 24 formed in a topthereof that is sized, shaped and threaded for mating with a set screw,such as the set screw 11′, best illustrated in FIG. 7. Each of theillustrated open bone screws 18 includes a head or upper portion 27integral with a lower shank 28 having at least one helical thread formfor rotating and driving the screw into a vertebra. The head 27 is inthe form of opposed arms that form an open channel 30 sized and shapedto closely receive the rod 14 in an open or percutaneous manner andhaving a guide and advancement structure, illustrated as a flange form31 for rotating into and mating engagement with a closure top such as aclosure top 35 shown in FIGS. 3 and 5, for example. Details of both openand closed screws and closures, such as the screws 11 and 11′ and theclosures 35 for use with longitudinal connecting member embodiments ofthe invention are described in greater detail in Applicant's U.S. patentapplication Ser. No. 13/506,657 filed May 7, 2012, published as US2012/0221054, the entire disclosure of which is incorporated byreference herein (and hereafter identified as the '657 application). Forexample, certain open screws are shown in FIGS. 33-43 of the '657application and certain closed bone screws are shown in FIGS. 69-71 ofthe '657 application. The '657 applications also discloses a variety ofset screws and closure tops for use with the bone screws describedtherein. In the present application, although the assembly 1 softsegment 3 is shown with closed screws, it is noted that the soft segment3′ may also be used with open bone screws, both monoaxial and polyaxial,as described, for example, in Applicant's '657 application. It is alsonoted that although the soft segment 3 is shown with the cord grippingclosure top 11′ and another of the closed screws 16 is shown without aclosure, in certain embodiments, the bone anchors used with the softsegment 3 may also be used with non-gripping closures that allow for thecord 4 to slip or slide with respect to the closure as described indetail in Applicant's '657 application.

The tensioned cord 4, spacer 6, bumpers 8 and blocker 10 with set screw11 are identical or substantially similar to the longitudinal connectingmember components identified by the same names and described in greaterdetail in Applicant's '657 application, the disclosure of which hasalready been incorporated by reference herein. For example, a tensionedcord 1004 is shown in FIGS. 28-32 of the '657 application and describedin paragraph 146 therein that is the same or substantially similar inform and function to the tensioned cord 4. Spacers 1006 and 2006, forexample, are shown in FIGS. 30-32 and 44-49, respectively, of the '657application and described in paragraphs 147 and 168-72 therein that arethe same or substantially similar in form and function to the spacer 6.Bumpers 1008 and 2008, for example, are shown in FIGS. 30-32 and 44-49,respectively, of the '657 application and described in paragraphs 148-49and 168-72 therein that are the same or substantially similar in formand function to the elastic bumpers 8. A blocker and set screwcombination 2010, 2011 is shown in FIGS. 44-49 of the '657 applicationand described in paragraph 170 therein that is the same or substantiallysimilar in form and function to the end blocker 10 and set screw 11combination. Spacers 6 and bumpers 8 of embodiments of the invention aretypically cylindrical tubes prior to assembly, but may be formed inother geometric shapes. Also, it is noted that the illustrated elasticbumpers 8 shown in the drawings are shown compressed in the drawingfigures and thus are not shown as cylinders, but rather in a compressedform wherein the bumper bulges outwardly at a middle portion thereof.

With particular reference to FIGS. 1 and 2, the off-set connector 2 canalso be described as a double-wide blocker, with one portion of theconnector sized and shaped for receiving a tensioned cord and anadjacent portion sized and shaped for receiving another connector, suchas a hard rod. The illustrated connector 2 includes a first through boredefined by a substantially cylindrical surface 50 and a second, parallelthrough bore formed by a substantially cylindrical surface 52, both borecylindrical surfaces 50 and 52 formed in the connector 2 between andthrough substantially planar front 54 and rear 56 surfaces. The frontsurface 54 is parallel to the rear surface 56. A top surface 58perpendicular to both the front surface 54 and the rear surface 56 issubstantially planar and terminates at the front and rear surfaces 54and 56. In the illustrated embodiment, opposed side surfaces 60 and 62are each curved and also terminate at the top surface 58. A bottomsubstantially planar surface 65 spans between the curved side surfaces60 and 62. However, it is foreseen that in other embodiments of theinvention the bottom surface 65 may include cut-outs and curves. Thecylindrical surface 50 is located near the side surface 60 and thecylindrical surface 52 is located near the side surface 62, thecylindrical surfaces 50 and 52 being uniformly spaced from therespective side surfaces 60 and 62. Formed in the top surface 58 are apair of spaced apertures defined by threaded cylindrical surfaces 70 and72. The cylindrical surface 70 runs from the top surface 58 andterminates at the bore 50 while the cylindrical surface 72 runs from thetop surface 58 and terminates at the bore 52. Thus apertures defined bythe surfaces 70 and 72 communicate with and are perpendicular to thebores defined by the respective cylindrical surfaces 50 and 52. Thethreaded surface 70 is sized and shaped for mating engagement with a setscrew 111, as shown for example in FIG. 3a , and the threaded surface 72is sized and shaped for mating engagement with a set screw 111′, shownin both FIG. 3 and FIG. 3a . It is noted that in the embodimentillustrated in FIG. 3a , the set screws 11, 11′ and 111 are identical.However, in other embodiments of the invention, set screws or closuretops of different sizes or geometries may be utilized to press thetensioned cord 4 into frictional engagement with other connectors, endblockers or bone screws.

In the illustrated embodiment, the through bores defined by thecylindrical surfaces 50 and 52 are substantially the same size, allowinga user to laterally connect any two longitudinal connecting memberassembly segments, either soft or hard without concern of how to orientthe connector 2 with respect to such segments. Thus, the connector 2 maybe used with or without a hard rod. For example, two soft connectorsegments, possibly having spacers or bumpers of different durometer orsegments that differ only in length may be medially/laterally connectedin a staggered manner by the connector 2. Similarly, both the threadedbores 70 and 72 are shown having the same diameter and thus only theclosures or screws would need to be different in height to adequatelyfix against a hard rod 14 or a soft tensioned cord 4. As shown in FIGS.6 and 7, for example, the set screws 11 and 11′ shown in FIG. 7 eachinclude a central projection 12 and 12′ respectively, for pressingdownwardly against the cord 4 while the set screw 111′ shown in FIG. 6is of a shorter length than the screws 11 and 11 and includes an edge orshallow rim 112′ for gripping and penetrating the hard rod 14. In otherembodiments, the screw 111 may include other surfaces, points or edgesfor gripping the rod 14 or may have a planar bottom surface.

It is foreseen that in other embodiments of the invention, thecylindrical surface 50 that slidingly receives the cord 4 may have adiameter that is smaller than a diameter of the surface 52 thatslidingly receives the rod 14. Also, the set screw receiving surfaces 70and 72 may have different diameters, thus requiring various set screwsof not only different heights but also different diameters forcooperating with either side of the connector 2.

With further reference to FIGS. 3 and 4-7, the assembly 1 is shownwherein the cord 4 is fixed to the end blocker 10 at a first endthereof, the set screw 11 pressing the cord 4 into frictional engagementwith the blocker 10. The cord 4 is then threaded through one of theelastic bumpers 8 and then through the head 21 of one of the bone screws16. The cord 4 is then threaded through the inelastic spacer 6 and theconnector 2, followed by another elastic bumper 8 and finally the head21 of the bone screw 16 that also includes the set screw 11′ that fixesthe cord 4 to the bone screw 16. The cord 4 is in sliding relation withboth bumpers 8, the bone screw 16 that is located between one of thebumpers 8 and the spacer 6. The cord 4 is also in sliding relation withthe connector 2, the threaded cylindrical surface 70 being shown withouta set screw. The soft segment 3 of the assembly 1 is shown in a nominalstate, as, for example, the assembly would be in after the cord 4 istensioned (in some embodiments, after the cord 4 has had some extensionafter creep and wherein the cord 4 may have been re-tensioned andrecaptured at either the bumper 10 or the set screw 11′. As shown,tensioning of the cord 4 results in some compression placed on thebumpers 8. As best shown in FIG. 7, the cord 4 is in tension between theblocker 10 and the end screw 16 that has the set screw 11′ pressingagainst the cord 4. The cord 4 is free to slide with respect to all thesoft segment components located between the blocker 10 and the end screw16, allowing the soft segment 3 to respond to compressive and extensionforces on vertebrae (not shown) attached to both of the bone screws 16.As shown in FIG. 3 and FIGS. 47, the hard rod 14 is fixed to theconnector 2 by the set screw 111′ and is fixed to three bone screws 18by three closure tops 35.

With reference to FIG. 3a , the assembly 1 has been modified to createan assembly 1′ wherein a soft segment 3″ has the cord 4 fixed at one endby the blocker 10 and at an opposite end thereof by the set screw 111rotatingly mated with the threaded cylindrical surface 70 of theconnector 2. Thus, the connector 2 is also a termination of the softsegment 3″, the connector 2 functioning as an end blocker for thetensioned cord 4. The tensioned cord 4 is in sliding relation with abumper 8, a bone screw 16 and a spacer 6. The bone screw 16 is shownwith the opening 24 empty, similar to what is shown in FIG. 3. However,in some embodiments of the invention, it may be desirable to insert aset screw 11′ in the bone screw head 21 to fix the cord 4 to the bonescrew 16. In such an embodiment, a bumper 8 may be placed on an oppositeside 56 of the connector 2 and the cord threaded through an additionalend blocker 10 located adjacent such bumper 8. Thus, a wide variety ofcombinations of bumpers, blockers, spacers and bone screws for a softsegment can be visualized. In the embodiment illustrated in FIG. 3a ,the connector 2 is fixed to the hard rod segment 3′ identical to what isshown in FIG. 3. However, it is foreseen that hard rod segments ofdifferent lengths or other hard or soft segments may be slidinglycaptured by the connector 2 or fixed to the connector 2 by a set screw111 or 111′ in lieu of the rod segment 3′ shown.

With reference to FIGS. 8 and 9 another embodiment of a connector 2′ isshown. The connector 2′ is similar to the connector 2 previouslydescribed herein with the exception that an open channel for a rod isformed in the connector 2′ in lieu of the rod receiving through bore 52and set screw aperture 72 combination. Thus, the connector 2′ includes acylindrical surface 50′ defining a through bore, a front surface 54′, arear surface 56′, a top surface 58′, a curved side surface 60′, a bottomsurface 65′ and a threaded aperture 70′ substantially similar in formand function to the respective cylindrical surface 50, front surface 54,rear surface 56, top surface 58, curved side surface 60, bottom surface65 and threaded aperture 70 previously described herein with respect tothe connector 2. The connector 2′ also includes a side portion 27′defining a rod receiving channel 30′ further defined by a guide andadvancement structure that is shown as a flange form structure 31′ forreceiving a closure top 35′ that is substantially similar in form andfunction to the respective bone anchor upper portion or head 27 definingthe rod receiving channel 30 further defined by the flange form guideand advancement structure 31 for receiving the closure top 35 previouslydescribed herein with respect to the open bone anchor 18. As shown inFIG. 8, the rod 14 is received in the connector 2′ channel 30′ and theclosure top 35′ is rotated with respect to the flange form 31′ tocapture and fix the rod 14 within the connector 2′. Similar to what hasbeen discussed previously herein, with respect to FIG. 8, a tensionedcord 4 is shown fixed to the connector 2′ by a set screw 111 insertedwithin the opening 70′ at the top 58′ of the connector 2′. FIG. 8 alsoshows a partial spacer 6 disposed about the tensioned cord 4 and furthersoft connector components, including bumpers, additional bone anchorsand end blockers may be connected by the tensioned cord 4 at an oppositeside of the spacer 6.

With respect to FIG. 9, the alternative connector 2′ is shown with a rod14 and closure top 35′ similar to what is shown in FIG. 8 and furthershown with a tensioned cord 4 is sliding engagement with the connector2′, the connector aperture surface 70′ not having a set screw 111rotatingly mated therein. The cord 4 is shown in sliding engagement witha bumper 8 and being fixed to an end blocker 10 with a set screw 11.Similar to FIG. 8, FIG. 9 shows a partial spacer 6 surrounding thetensioned cord 4 at the back surface 56′ of the connector 2′. A bonescrew (not shown) may be placed at an opposite end of the spacer 6 thatmay be in fixed or slidable engagement with the cord 4. Further bumpers8, spacers 6, bone anchors and possibly another end blocker 10 may belocated along the tensioned cord 4.

With reference to FIG. 10, another alternative connector, generally 201,is shown. The connector 201 includes a closed connector portion 202integral with a bone screw, generally 218. Thus the connector portion202 includes a cylindrical surface 250 defining a through bore, a frontsurface 254, a rear surface 256, a top surface 258, a curved sidesurface 260, a bottom surface 265 and a threaded aperture 270perpendicular to the cylindrical surface 260 that is substantiallysimilar in form and function to the respective cylindrical surface 50,front surface 54, rear surface 56, top surface 58, curved side surface60, bottom surface 65 and threaded aperture 70 previously describedherein with respect to the connector 2. The connector 202 also includesa head portion 227 that is integral to the connector portion 202 and ashank 228, the head portion 227 defining a rod receiving channel 230further defined by a guide and advancement structure that is shown as aflange form structure 231 for receiving a closure top 235 that issubstantially similar in form and function to the respective bone anchor18 upper portion or head 27 and shank 28, the head 27 defining the rodreceiving channel 30 further defined by the flange form guide andadvancement structure 31 for receiving the closure top 35 previouslydescribed herein with respect to the open bone anchor 18.

It is foreseen that a connector may also include two open channels, onefor receiving a rod and the other for receiving a cord 4. Furthermore,such a dual open channel embodiment could be integral with a bone screwshank.

It is to be understood that while certain forms of the present inventionhave been illustrated and described herein, it is not to be limited tothe specific forms or arrangement of parts described and shown.

1. A longitudinal connecting member assembly having first and secondbone anchors spanning between first and second vertebrae, the assemblycomprising: a) a soft portion having a cord in continuous tension, thecord being in slideable relation with the first bone anchor, wherein theanchor is positioned between an end blocker-bumper and a spacer; b) ahard portion being in fixed relation with the second bone anchor; c) aconnecting structure in fixed relation with the hard portion and in oneof a fixed and a sliding relation with the cord, the connectingstructure positioning the soft portion in a lateral and staggeredrelation with the hard portion; d) a hard end structure fixed to thecord; and e) an elastic bumper and a spacer both being in slidablerelation with the cord, the elastic bumper positioned between the endstructure and the first bone anchor, the first bone anchor beingpositioned between the elastic bumper and the spacer.
 2. The assembly ofclaim 1 further comprising a third bone anchor attached to a thirdvertebra, the third bone anchor fixed to the hard structure.
 3. Theassembly of claim 1 further comprising a third bone anchor attached to athird vertebra, the third bone anchor fixed to the cord, the cord inslidable relation with the connecting structure.
 4. The assembly ofclaim 1 wherein the elastic bumper is a first bumper and furthercomprising a second elastic bumper, the first and second bumpers locatedon either side of the connecting structure.
 5. The assembly of claim 4further comprising a third bone anchor fixed to the cord, the firstbumper located adjacent the first bone anchor and the second bumperlocated adjacent the third bone anchor.
 6. The assembly of claim 1wherein the connecting structure has a first through bore for receivingthe cord and a second through bore for receiving the hard portion, thefirst and second through bores being parallel.
 7. The assembly of claim6 wherein the connecting structure has and a third bore disposedperpendicular to the first through bore and in communication therewithand a fourth bore disposed perpendicular to the second through bore andin communication therewith, the third bore having a thread for matingengagement with a set screw, the set screw sized and shaped forfrictionally fixing the cord against the connecting structure.
 8. Theassembly of claim 7 wherein the fourth through bore has a helical guideand advancement structure formed thereon, the guide and advancementstructure sized and shaped for mating engagement with a closure top, theclosure top fixing the hard portion within the connecting structure. 9.The assembly of claim 1 wherein the hard portion is a cylindrical rod.10. The assembly of claim 1 wherein the connecting structure is integralwith a third bone anchor.
 11. The assembly of claim 1 wherein the hardportion is a cylindrical rod and the connecting structure has an openchannel sized and shaped for receiving the hard rod.
 12. In a spinallongitudinal connecting member assembly having a soft segment and a hardrod segment, the soft segment having a tensioned inner core, thetensioned inner core being captured within a first bone anchor and therod segment being attached to second and third bone anchors, theimprovement comprising: a) a connector structure oriented transverse toboth the soft segment and the hard rod segment, the connector structurefixed to the hard rod and capturing the tensioned inner core, theconnector structure being in one of sliding and fixed relation to thetensioned inner core, the inner core being in sliding relation withrespect to the first bone anchor; and b) a rigid end blocker fixed tothe tensioned inner core and spaced from the connector structure.
 13. Aspinal connector structure for attaching a rod segment to a softstabilization longitudinal connecting assembly segment, the assemblyhaving a tensioned cord, a spacer surrounding the cord and a rigid endstructure fixed to the cord, the connector structure comprising: a) abody forming first and second parallel through bores, the first boresized and shaped for receiving and capturing the tensioned cord in asliding relation thereto and the second bore sized and shaped forreceiving and capturing the rod, the first and second bores placing thesoft stabilization segment and the rod segment in staggeredlateral/medial parallel orientation to one another, the body also havingan open channel communicating with and disposed perpendicular to thesecond through bore, the channel sized and shaped for receiving the rod,the channel being partially defined by a first helically wound flangeform; and b) a closure structure extending into the aperture having asecond helically wound flange form sized and shaped for matingengagement with the first flange form, the closure structure being sizedand shaped for frictional engagement with the rod located in the secondbore.
 14. The spinal connector structure of claim 13 wherein theconnector structure is a bone anchor having a shank.
 15. A longitudinalconnecting member assembly having first and second bone anchors spanningbetween first and second vertebrae, the assembly comprising: a) a firstelongate segment having an inner cord in continuous tension and having asteady state length, the cord being surrounded by at least one of aspacer and a blocker, the cord being in slideable relation with thefirst bone anchor; a second elongate segment attached to the second boneanchor; and b) a connecting structure capturing the second elongatesegment, the connecting structure being in one of a fixed and a slidingrelation with the tensioned cord, the connecting structure positioningthe first elongate segment in an off-set and staggered relation with thesecond elongate segment.
 16. The assembly of claim 15 wherein the secondelongate segment is a hard rod fixed to the first bone anchor.